Summary
Geochemical-mineralogical characteristics of lead-zinc ores in the Tó LÖ area
NguyÔn V¨n Nh©n, Hoµng Minh Th¶o
In the Tó LÖ area, there are many lead-zinc deposits such as Huéi Pao, Co Gi San, Tó San, B¶n L×m, NËm ChËu... They are located in orthophyre, quartz orthophyre, volcano-sedimentary beds and sericite shale of Jurassic-Cretaceous age. The main minerals are sphalerite and galenite. The minor minerals are pyrite, boulangerite, chalcopyrite, arsenopyrite, tetraedrite, pyrrhotine, hematite, semseyite. Native gold is also present. Gangue phases include quartz, chalcedony, carbonate and chlorite. Structures of ore are extensively gel-zone, rhythmic band, breccia, vein. Ore deposits belong to medium-low temperature hydrothermal group.
The Tó LÖ deposit can be assigned to the galenite-sphalerite-sulfoantimonide Pb formation with 3 mineralization types:
- Au-bearing sphalerite (galenite) such as in Huéi Pao;
- Ag-rich galenite-sulfoantimonide Pb such as in Co Gi San;
- Cu-rich sphalerite-galenite-chalcopyrite such as in Tó San, B¶n L×m
The Tó LÖ lead-zinc mineralization is close related to felsic-alkaline effusives and rocks of Jurassic-Cretaceous age. A part from Pb-Zn, the ores are still rich in Ag, Au.
Ngµy nhËn bµi: 07-08-2001
Ngêi biªn tËp: D¬ng §øc Kiªm